This 1950 Hitchcock film came between Under Capricorn and Strangers on a Train, and if it isn't the equal of those two sterling achievements, it's still an intriguing experiment. It's a murder mystery set in the stage world of London, and almost every scene features some sort of deception, from theatrical performance to bald-faced lying. Even the director, it turns out, isn't to be trusted. The issues aren't satisfactorily resolved, but Hitchcock seems to be exploring the ways in which various falsehoods—the falsehoods of acting, storytelling, and art in general—can lead to the truth, and the equally powerful ways in which they can betray it. There is also some very strange business involving a Cub Scout and a bloody doll, but that image, perhaps, is best left unexplored. With Marlene Dietrich, Jane Wyman, and Michael Wilding. 110 min.